Electrical switch

ABSTRACT

An electrical switch includes a first pivotally mounted actuating member, the rocking movement of which is transmitted to a second pivotally mounted actuating member whose rocking movement effects the operation of a leaf spring over its dead center position to open and close the switch contacts. The said first actuating member has a depending lug which engages with and rides over sloping ramps forming part of the said second actuating member.

United States Patent Howe [451 June 13, 1972 ELECTRICAL SWITCH FOREIGNPATENTS OR APPLICATIONS [72] In entor: John Arthur Howe, Chilwell,England 978,491 12/1964 Great Britain ..200/68 [73] Assignee: TRW Inc.Cleveland, Ohio 1,088,616 10/1967 Great Britain ..200/68 Filed! J y 1970Primary Examiner-David Smith, Jr. [211 App! NOJ 53,362 Attorney-PhilipE. Parker, Gordon Needleman, James R. O-

Connor, John Todd and Hall & Houghton [30] Foreign Application PriorityData [57] ABSTRACT y 14, 1969 Great Britain An electrical switchincludes a first pivotally mounted actuat- U Cl ing member, the rockingmovement of which is transmitted to [5;] I .tS.Cl ..200/67 G a Secondpivotally mounted actuating member whose rocking E 2 1 movement effectsthe operation of a leaf spring over its dead m 6 c center position toopen and close the switch contacts. The said 5 6] References Cited firstactuating member has a depending lug which engages UNITED STATES PATENTSHeath ..200/68 X with and rides over sloping ramps forming part of thesaid second actuating member.

3 Claims, 7 Drawing Figures PATENTEDJuu 1 3 m2 SHEET 10F 2 INVENTORgRTgUR HOWE JOHN ATTORNEY PATENTEDJUH 13 m2 SHEET 2 BF 2 INVENTORATTORNEY ELECTRICAL SWITCH This invention relates to an electricalswitch of the kind which is operated by rocking or pivotal movement ofan actuating member.

According to the present invention, the switch comprises a housingformed of insulating material having at least one fixed and one movablecontact and a snap-over leaf spring for moving the movable contact intoand out of engagement with the co-operating fixed contact, a switchactuating member being pivotally mounted in the housing and providedwith a lug engaging an intermediate actuating member comprising a basepivotally mounted in the housing, one face of the intermediate memberhaving a projection engaging the leaf spring and the opposite facehaving ramp-like surfaces extending in angular relation to one anotherto define an obtuse angle, the apex of which is approximately at thepivotal center of the base, the arrangement being such that the rockingor pivotal movement imparted to the first mentioned actuating memberwill cause the lug thereon to ride over one or other of the rampsurfaces so as to pivot the intermediate actuating member whereby theprojection thereon will move the leaf spring over one or other sides ofits dead center so as to snap the intermediate actuating member into aposition to cause the spring to effect the movement of the movablecontact relative to the fixed contact to open or close the switch.

The movable contact may be mounted on the leaf spring.

In one embodiment the switch includes two fixed contacts and two movablecontacts co-operating therewith, a separate leaf spring and a separateintermediate actuating member being provided for each pair of fixed andmovable contacts, the ramp surfaces of the respective intermediateactuating members and their operation by the lugs on the first mentionedactuating member being such that the latter is capable of moving intothree positions in one of which both movable contacts engage both fixedcontacts, in the second position both movable contacts are in spacedrelation to their associated contacts and in the third position onemovable contact engages its fixed contact and the other is spaced fromits fixed contact.

To enable the invention to be fully understood, it will now bedescribed, by way of example, with reference to the accompanyingdrawings in which:

FIG. 1 is a sectional side view of a switch according to one embodimentof the invention;

FIG. 2 is an end elevational view of the switch;

FIG. 3 is a plan view thereof;

FIG. 4 is a plan view of the switch with the actuating member removed;and

FIGS. 5, 6 and 7 are sectional side views illustrating the threeoperative positions of the switch.

As shown, the switch comprises a housing 1 formed of insulating materialsuch as resilient or semi-resilient synthetic plastics having a pair offixed contacts 2 on the inner face of the bottom wall 3 and connected toa terminal 4 which extends through a slot in the bottom wall to theexterior of the housing to enable a lead wire to be attached. A furtherpair of terminals 5 extend through slots in the bottom wall 3 and eachincludes a portion 5a projecting inwardly of the housing substantiallyat right angles thereto. The terminals 5 also have portions extendingoutwardly of the housing to enable a lead to be attached thereto.

The housing is divided into two compartments by a partition and a saidfixed contact 2 and terminal posts 4 and 5 are positioned in eachcompartment.

A snap-over leaf spring is also assembled in each compartment andincludes an arm 6 pivoted at anintermediate point in its length to theprojecting portion 5a of the terminals 5. The spring also includes anarm 7 overlying the arm 6 in spaced relation thereto and connected withthe arm 6 by a resilient bight 8. The free end of the arm 6 carries amovable contact 9 for co-operative engagement with the fixed contact 2and the free end of the arm 7 is reversely bent to form a V- shapedrecess or groove 10.

The housing 1 is open at its upper end as viewed in FIG. 1 and a switchactuating member 11 is pivotally mounted in this open end by means oflateral pins 12 rotatably engaging in apertures in the opposed sidewalls of the housing. The underside of the member 11 is provided withtwo triangular shaped lugs l3, 14, which are angularly disposed to oneanother.

Two intermediate actuating members are mounted in the housing, one ineach compartment and each comprises a base 15 pivotally mounted bylateral pins 16 respectively engaging in an aperture in an adjacent sidewall of the housing and a recess lb in the partition la. The shape anddimensions of the apertures and recesses are such as to permit the pins16 a limited amount of movement in a vertical direction as viewed inFIG. 1.

The base of the respective intermediate members is provided with a pairof ramp-like surfaces 17, 17a and 18, 18a, the surfaces of each pairbeing disposed in angular relation so as to define an obtuse angle theapex of which is approximately at the central pivot point of the base.The ramps face the lugs 13, 14, which in operation of the switch areadapted to ride over one or other of the ramps. The underside of thebase 15 of the intermediate actuating members is formed with atriangular shaped projection 19 engaging in the recesses 10 of therespective leaf springs.

It will be noted that the central longitudinal axis of the lugs 13, 14,of the actuating member 11 is offset slightly with respect to a planeextending at right angles to the longitudinal axis of the member 11 andpassing through the pivotal axis thereof. 7

The arms of the leaf spring are normally under tension such that thearms 7 will be urged into engagement with the triangular projection 19of the intermediate actuating member and by virtue of the shape anddimensions of the apertures and recesses in which the pins 16 arereceived, the ramps of the intermediate actuating members will always beurged towards the lugs 13, 14, so as to make contact therewith and takeup any play.

By reason of the offset disposition of the lugs 13, 14, they will engagethe ramps of the respective intermediate members at different locationsand by virtue of the limited vertical movement of the pins 16, each lugcan be moved along the ramps past the center or apex of the anglesdefined by the pairs of ramps. This permits the switch to be operatedinto three positions. Firstly, to move both movable contacts to engageboth fixed contacts, secondly to position both movable contacts inspaced relation to the fixed contacts and thirdly, to position onemovable contact in engagement with a co-operating fixed contact whilethe other movable contact is in spaced relation to its associated fixedcontact.

In operation, when the actuating member 11 is pivoted, the lugs 13, 14,will ride over the ramps of the respective intermediate actuatingmembers causing the latter to pivot. Only a limited pivotal movementneeds to be imparted to the intermediate members until the snap-overleaf springs pass the dead center when they serve to complete themovement of the intermediate actuating members and effect a rapidmovement of the arms 6 of the leaf springs to engage or move away fromthe fixed contacts.

The operation of the switch in the form illustrated in the drawings isbest understood from a consideration of FIGS. 5 to 7. In FIG. 5, theactuating member 11 has been pivoted into a position wherein the lugsl3, l4, engage the ramps 17a, 18a of the respective intermediateactuating members such that both have been pivoted in a clockwisedirection and the projections 19 exert pressure on the arms 7 of theleaf springs which pressure is transmitted through the bight 8 to thearms 6 to urge both movable contacts 9 into engagement with the fixedcontacts 2. In moving to this position the lug 13 would have effectedthe pivotal movement of its co-operating intermediate actuating memberbefore the lug 14 effects the pivotal movement of the other intermediateactuating member. To permit the continued pivotal movement of the member1 1 for the lug 14 to actuate its intermediate actuating member, it willbe noted that the lug 13 has travelled a short distance along the ramp17a from the apex of the angle defined by the ramp surfaces. Thismovement is possible by reason of the limited vertical movementpermitted by the pivot pins 16. When the parts are in this position, thetwo leaf springs and the two intermediate actuating members are in lineand therefore only one of each of these parts is visible in the drawing.

FIG. 6 illustrates the position of the parts when the switch is in itsother extreme position, the actuating member 11 having been pivoted inan opposite direction to that referred to in connection with FIG. sothat both intermediate actuating members have been pivoted in ananti-clockwise direction and the pressure exerted by the projections 19,19a on the respective leaf springs is released and, as shown, the arms 6of the leaf springs have risen to permit the movable contacts toseparate from the fixed contacts. As the switch moves into the positionillustrated in FIG. 7, the lug 14 would have pivoted its associatedintermediate actuating member before the lug 13 pivots its member, andit will be noted that the lug 14 is moved slightly towards the left awayfrom the apex of the angle.

As in the case of FIG. 5, the two intermediate actuating members and theassociated leaf springs and contacts will be in line in this position ofthe switch and therefore only one of each of these parts is visible.

In the third position of the switch illustrated in FIG. 6, the switch isin a position corresponding to that illustrated in FlG. l, and the lug13 of the actuating member 11 has pivoted the intermediate actuatingmember shown in full lines in a clockwise direction, such that theprojection 19 exerts pressure on the leaf spring to cause the arms 6 tourge the movable contact into engagement with its co-operating fixedcontact. The lug 14 has not, however, reached the apex of the angle ordead center of the intermediate actuating member (shown in chain lines)and the pressure exerted on its associated leaf spring by the projection19 is such that the arms 6 are permitted to rise to separate the movablecontact from its cooperating fixed contact. Accordingly, in the positionillustrated in FIG. 6, one pair of movable and fixed contacts are inengagement and the other pair is separated from one another.

I claim:

1. An electrical switch comprising a housing formed of insulatingmaterial, at least two fixed contacts and two movable contacts andsnap-over ramp springs for moving the movable contacts, a first switchactuating member pivotally mounted in the housing and provided with afirst lug and a second lug, angularly disposed to one another, a secondswitch actuating member comprising a base pivotally mounted in thehousing, one face of said second actuating member having projectionsengaging the ramp springs and the opposite face provided with a pair oframp like surfaces, the surface of each pair extending in angularrealtion to one another to define at least two obtuse angles, the apexsof which are approximately at the pivotal center of the base, each lugengages a ramp-like surface, the arrangement being such that rocking orpivotal movement imparted to said first actuating member will cause thefirst lug to ride over the first ramp like surface and the second lug toride over the second ramp like surface so as to pivot said secondactuating member whereby the projection on the latter will move the rampspring over one or other sides of its dead center so as to snap saidsecond actuating member into a position to cause said spring to offsetthe movement of the mova ble contact relative to the fixed contact toopen or close the switch.

2. A switch according to claim 1, wherein the means pivotally supportingthe said first arm of said leaf spring comprises an inwardly extendingportion of a terminal post which includes a portion extending outwardlyof the housing.

3. A switch according to claim 1, wherein the said second arm is formedwith a recess into which the free end of the said projection on saidsecond actuating member extends.

1. An electrical switch comprising a housing formed of insulating material, at least two fixed contacts and two movable contacts and snap-over ramp springs for moving the movable contacts, a first switch actuating member pivotally mounted in the housing and provided with a first lug and a second lug, angularly disposed to one another, a second switch actuating member comprising a base pivotally mounted in the housing, one face of said secOnd actuating member having projections engaging the ramp springs and the opposite face provided with a pair of ramp like surfaces, the surface of each pair extending in angular realtion to one another to define at least two obtuse angles, the apexs of which are approximately at the pivotal center of the base, each lug engages a ramp-like surface, the arrangement being such that rocking or pivotal movement imparted to said first actuating member will cause the first lug to ride over the first ramp like surface and the second lug to ride over the second ramp like surface so as to pivot said second actuating member whereby the projection on the latter will move the ramp spring over one or other sides of its dead center so as to snap said second actuating member into a position to cause said spring to offset the movement of the movable contact relative to the fixed contact to open or close the switch.
 2. A switch according to claim 1, wherein the means pivotally supporting the said first arm of said leaf spring comprises an inwardly extending portion of a terminal post which includes a portion extending outwardly of the housing.
 3. A switch according to claim 1, wherein the said second arm is formed with a recess into which the free end of the said projection on said second actuating member extends. 